The US military is investigating allegations that American soldiers may raped an Iraqi woman and murdered her and three members of her family, including a child.

Confirming another major investigation into alleged killing and abuse of Iraqi civilians by at least three US soldiers, one officer said the incident in March just south of Baghdad had initially been blamed on insurgents active in the area.

The probe is the latest in a series launched in recent weeks since the revelation of investigations into the killings of 24 people in Haditha in November.

Officers said a criminal probe was launched on June 24 into whether soldiers killed four people in their home at Mahmudiya on March 12.

Police in the district said they could not recall a case meeting the description given by the US military.

Major-General James Thurman, the commander of the Baghdad area, ordered the army's Criminal Investigation Command to mount a full investigation within a day of two soldiers coming forward, the military said in its brief initial statement.

Major Todd Breasseale, a US military spokesman, said in Baghdad: "We're not going to leave any stone unturned."

The suspicion

In Washington, an army official said the suspicion was that two soldiers from the 502nd Infantry Regiment, later seen with blood on their uniforms, had raped a young woman and then one of them killed her and three of her family, among them a child.

The Pentagon said yesterday it was pursuing a new war crimes investigation into five American soldiers, alleged to have raped and murdered a young Iraqi woman and killed three members of her family in their home.

Yesterday's investigation is the fourth alleged war crime in Iraq to come to light in a matter of weeks, putting the Pentagon's legal system to its most stringent test since the Vietnam war.

In the latest suspected war crime, it is believed the woman's body was burnt, and that a child was killed along with two other Iraqi adults in the family's home.

The alleged rape and murders are believed to have taken place in the town of Mahmoudiya, about 18 miles south of Baghdad several months ago. The events were brought to the attention of the authorities on June 23 by two soldiers who saw blood on their comrades' clothing and heard them talking about the incident.

A day later the army launched an investigation. "A preliminary inquiry conducted by MND-Baghdad found sufficient information existed to recommend a criminal investigation into the incident," according to a statement released yesterday.

Military officials in Baghdad and Washington gave only sparse details of the incident. However, it is believed that at least one of the soldiers had confessed to involvement in the incident and four had had their weapons taken away and were confined to barracks. All are believed to be enlisted men.

The investigation, ordered by Major General James Thurman, the commander of coalition forces in Iraq, was announced at a time when the Pentagon is under severe pressure to improve the image of its troops - and its judicial system - following a series of high-profile atrocities against Iraqi civilians.

The most damaging of these are the events in the town of Haditha last November in which US Marines are accused of killing two dozen Iraqi civilians in retaliation for the death of one of their own in a roadside bombing. Separate Marine units attempted to cover up the deaths.

The killings, which have been widely likened to the notorious My Lai massacre at Vietnam, might never have come to light if not for a report in Time magazine.

More recent episodes have also exposed efforts by soldiers to cover up crimes against Iraqi civilians. Last week four enlisted men were charged with killing three Iraqi men at a former chemical plant and threatening a fellow soldier if he reported the deaths.

Meanwhile, seven Marines and one sailor were charged with killing a disabled Iraqi man in the town of Hamdania, west of Baghdad, placing a shovel near his body to suggest he had been planting a makeshift bomb.

The US military has opened a criminal investigation into the alleged killing of an Iraqi family by US soldiers.

Little official detail has been given, but unnamed officials say the inquiry includes the alleged rape of one of the victims before she was killed.

The investigation began on Saturday and follows an initial military inquiry.

The probe is the latest in a series of inquiries into alleged abuse of Iraqis by US troops.

The US Army's Criminal Investigation Command was asked to look into the incident after a preliminary military inquiry found reason to open a criminal probe, the military said in a statement in Baghdad.

'No stone unturned'

The criminal investigation was ordered a day after two soldiers said they had heard about the incident in the area of Mahmudiya, south of Baghdad, on 12 March, the statement said.

Unnamed officials said that at least two soldiers from the 502nd Infantry Regiment were being investigated to find out if they had been involved in allegedly raping an Iraqi woman, killing her and three other family members - including a small child, and burning her body.